The present invention relates to control systems for reciprocating linear motion devices or intermittent motion devices, for example, to systems for controlling the metering cylinder of a filling device in packaging machines, a lifting device for the containers to be filled with a liquid by the filling device, a transport device for intermittently transporting the liquid-filled containers, etc.
Conventionally, the filling stroke of filling devices is controlled by a cam. A cam is also used for controlling the lift stroke of lifting devices to maintain a constant distance between the filling nozzle and the level of the liquid filled in containers during filling operation. A cam is also used for controlling the transport stroke of transport devices for intermittently transporting the liquid-filled containers to a specified work station, so as to diminish the movement of the liquid.
With conventional control systems wherein a cam is used for an operating member, there arises a need to change the cam when the amount of stroke of the operating member or the velocity thereof is to be altered. Accordingly, various cams must be prepared, while the change of the cam requires a cumbersome procedure.